Precursors for refractory paints and their use
The present invention relates to a dry refractory paint precursor composition comprising, 5 to 55 wt.-% mineral filler, 20 to 45 wt.-% glass frit comprising SiO 2 , Na 2 O, B 2 O 3 and/or Al 2 O 3 , and 0.1 to 25 wt.-% of a binder selected from waterglass, cement and mixtures thereof, all based on the total weight of the composition. The invention further relates to refractory paints comprising said compositions, and to methods for preparing said paints.
1. A dry refractory paint precursor composition comprising:
5 to 55 wt.-% mineral filler comprising aluminosilicate, silica, alumina, and/or mixtures thereof;
20 to 45 wt.-% glass frit comprising SiO 2 , Na 2 O, B 2 O 3 , Fe 2 O 3 , CoO, CaO, K 2 O, MgO and/or Al 2 O 3 ; and
0.1 to 25 wt.-% of a binder selected from waterglass, cement and mixtures thereof, all based on the total weight of the composition;
wherein the mineral filler comprises 30 wt.-% or more Al 2 O 3 .
2. A dry refractory paint precursor composition according to claim 1 , wherein the dry refractory paint precursor composition is a particulate composition.
3. A dry refractory paint precursor composition according to claim 1 , further comprising 0.1 to 35 wt.-% magnesia, based on the total weight of the composition.
4. A dry refractory paint precursor composition according to claim 1 , wherein the binder comprises waterglass, further wherein the waterglass is selected from sodium silicate, sodium metasilicate, or sodium metasilicate pentahydrate.
5. A dry refractory paint precursor composition according to claim 1 , wherein the binder consists of calcium aluminate or Portland cement.
6. A dry refractory paint precursor composition according to claim 1 , further comprising from 0.5 to 3 wt.-% boric acid or a fluxing agent.
7. A dry refractory paint precursor composition according to claim 1 , further comprising from 0.1 to 3 wt.-% of a rheological agent, wherein the rheological agent is selected from cellulose or methyl-hydroxyethyl cellulose.
8. A refractory paint comprising the dry refractory paint precursor composition of claim 1 .
9. A method of preparing a refractory paint, comprising mixing a dry refractory paint precursor composition of claim 1 with 65 wt.-% water, based on the total weight of the dry refractory paint precursor composition.
10. A method of preparing a refractory paint according to claim 9 , further comprising adding methyl-hydroxyethyl cellulose.
11. A method comprising applying a refractory paint according to claim 8 to a metallic part to protect said metallic part from dry corrosion, hot corrosion, pitting corrosion, galvanic corrosion, intergranular corrosion, stress corrosion, or another form of corrosion.
12. A method comprising applying a refractory paint according to claim 8 to a metallic part in an industrial furnace.
13. A method comprising applying a refractory paint according to claim 8 to a substrate, wherein applying the refractory paint improves a sintering property of a refractory composition or a refractory precursor composition.
14. A dry refractory paint precursor composition comprising:
5 to 55 wt.-% mineral filler comprising aluminosilicate, silica, alumina, and/or mixtures thereof;
20 to 45 wt.-% glass frit comprising SiO 2 , Na 2 O, B 2 O 3 , Fe 2 O 3 , CoO, CaO, K 2 O, MgO and/or Al 2 O 3 ; and
0.1 to 25 wt.-% of a binder selected from waterglass, cement and mixtures thereof, all based on the total weight of the composition;
wherein the mineral filler comprises 80 wt.-% or more SiO 2 .
15. A dry refractory paint precursor composition comprising:
5 to 55 wt.-% mineral filler;
20 to 45 wt.-% glass frit comprising SiO 2 , Na 2 O, B 2 O 3 , Fe 2 O 3 , CoO, CaO, K 2 O, MgO and/or Al 2 O 3 ; and
0.1 to 25 wt.-% of a binder selected from waterglass, cement and mixtures thereof, all based on the total weight of the composition,
further comprising from 0.05 to 2 wt.-% clay in addition to the mineral filler, wherein the clay is selected from kaolin, bentonite, smectite, and/or mixtures thereof.
16. A dry refractory paint precursor composition comprising:
5 to 55 wt.-% mineral filler;
20 to 45 wt.-% glass frit comprising SiO 2 , Na 2 O, B 2 O 3 , Fe 2 O 3 , CoO, CaO, K 2 O, MgO and/or Al 2 O 3 ; and
0.1 to 25 wt.-% of a binder selected from waterglass, cement and mixtures thereof, all based on the total weight of the composition,
further comprising from 0.05 to 7 wt.-% silica fume in the composition in addition to the mineral filler.